it's important to use unsortedCount rather than unsorted.length as flush() may be called when the unsorted array is not full due to its use in reserve. This could result in freed IDs leaking into the list twice

Author: David R. MacIver

src/com/rabbitmq/utility/IntAllocator.java

@@ -140,9 +140,9 @@ private void flush(){
     ListIterator<Interval> it = intervals.listIterator();
 
     int i = 0;
-    while(i < unsorted.length){
+    while(i < unsortedCount){
       int start = i;
-      while((i < unsorted.length - 1) && (unsorted[i + 1] == unsorted[i] + 1))
+      while((i < unsortedCount - 1) && (unsorted[i + 1] == unsorted[i] + 1))
         i++;
 
       Interval interval = new Interval(start, i);